elf: Fix hwcaps string size overestimation

Commit dad90d528259b669342757c37dedefa8577e2636 added glibc-hwcaps
support for LD_LIBRARY_PATH and, for this, it adjusted the total
string size required in _dl_important_hwcaps. However, in doing so
it inadvertently altered the calculation of the size required for
the power set strings, as the computation of the power set string
size depended on the first value assigned to the total variable,
which is later shifted, resulting in overallocation of string
space. Fix this now by using a different variable to hold the
string size required for glibc-hwcaps.

Signed-off-by: Javier Pello <devel@otheo.eu>
(cherry picked from commit a23820f6052a740246fdc7dcd9c43ce8eed0c45a)

diff --git a/elf/dl-hwcaps.c b/elf/dl-hwcaps.c
index 6f161f6ad528661f6b577d7d5d8a1f6ec6825363..92eb53790ef8d32005c0da5e28804bc5843a94d3 100644 (file)
--- a/elf/dl-hwcaps.c
+++ b/elf/dl-hwcaps.c
@@ -193,7 +193,7 @@ _dl_important_hwcaps (const char *glibc_hwcaps_prepend,
   /* Each hwcaps subdirectory has a GLIBC_HWCAPS_PREFIX string prefix
      and a "/" suffix once stored in the result.  */
   hwcaps_counts.maximum_length += strlen (GLIBC_HWCAPS_PREFIX) + 1;
-  size_t total = (hwcaps_counts.count * (strlen (GLIBC_HWCAPS_PREFIX) + 1)
+  size_t hwcaps_sz = (hwcaps_counts.count * (strlen (GLIBC_HWCAPS_PREFIX) + 1)
                  + hwcaps_counts.total_length);
 
   /* Count the number of bits set in the masked value.  */
@@ -229,11 +229,12 @@ _dl_important_hwcaps (const char *glibc_hwcaps_prepend,
   assert (m == cnt);
 
   /* Determine the total size of all strings together.  */
+  size_t total;
   if (cnt == 1)
-    total += temp[0].len + 1;
+    total = temp[0].len + 1;
   else
     {
-      total += temp[0].len + temp[cnt - 1].len + 2;
+      total = temp[0].len + temp[cnt - 1].len + 2;
       if (cnt > 2)
        {
          total <<= 1;
@@ -255,6 +256,7 @@ _dl_important_hwcaps (const char *glibc_hwcaps_prepend,
   /* This is the overall result, including both glibc-hwcaps
      subdirectories and the legacy hwcaps subdirectories using the
      power set construction.  */
+  total += hwcaps_sz;
   struct r_strlenpair *overall_result
     = malloc (*sz * sizeof (*result) + total);
   if (overall_result == NULL)